Cancer is considered to be the worst disease except the cardiovascular disease. At present chemotherapy and radiotherapy are frequently used for treatment of cancer, but their toxicant and side effect is very adverse for health. The specialists home and abroad have found that dendrobium, a kind of traditional Chinese medicine, can be antineoplastic, anti-aging and expanding blood vessel, and its extract by ethanol and the bibenzyl compounds have antineoplastic activity in vivo of different degrees. The active component of dendrobium has caught the attention of the world.
The findings of Wang Tianshan (In vitro Inhibition Activities on the Growth of Tumor Cell Strain K256 by Constituents from Dendrobium Chrysotoxum, Natural Product Research and Development, 1997, 9 (2), 1˜3) showed that bibenzyls and phenanthrenes have inhibitory effect on the assembling and caryocinesis of the in vitro cultured murine microtubulin L1210, P388 cell strain and many human tumor cell strains including A-549, MCF-7, HT-29, SKMEL-5, MLM, SK-OV-3, and HL-60. The dihydrobibenzyls and phenanthrenes in Dendrobium chrysotoxum have different degrees of inhibitory effect on the growth of tumor cell strain K256, among which Erianin (dihydrocombretastatin A-4) is the most active.
Erianin has the best effect on the liver cancer of mouse, its tumor inhibitory rate being 50.82%. Related study (Inhibitory effects of dendrobium chrysotoxum and its constituents on the mouse HePA and ESC, Journal of China Pharmaceutical University, 1994, 25 (3), 188˜189) infers that the side effect of Erianin is far lower then 5FU, the medicine for chemotherapeutics of cancer. Erianin have negative proton effect to many kinds of cancer cells, the effecting target being the microtubulin in the cell. It can inhibit the polymerizing of microtubulin, stimulate the hydrolization of microtubulin-dependent GTP, and competitively bind with protein with colchicine. The study of Li Yunman (Erianin Induces Apoptosis of Human leukemia HL-60 cells, Acta Pharmacologica Sinica, 2001, November, 22(11), 1018-1022) showed that Erianin significantly inhibited the growth of human leukemia HL-60 cells. The inhibition might be the result of the induced apoptosis and the altered expression of bcl-2 and bax genes in HL-60 cells.
The chemical name of Erianin is 2-methoxyl-5-[2-(3,4,5-trimethoxy phenyl)]ethyl phenol, its molecular formula being C18H22O5 and molecular weight being 318.35, and its chemical structural formula is as follows:

At present, the preparative process of Erianin is extracting Erianin from dendrobium by separating and extractive technique of Chinese materia medica. The Chinese patent application CN03115752.1 disclosed the method of extracting Erianin from dendrobium, comprising extraction by supercritical CO2 and column chromatography using absolute alcohol, methanol, acetone as entrainer to extract Erianin, the antineoplastic active component, from orchidaceae plants, dendrobium, using CO2 as extracting medium; The crude extract was chromatographed by a silica column using an eluting reagent of petroleum benzene: ethyl acetate solution, and recrystallizing to get the refined extractive.
As this method is of high technical specification, and the source of dendrobium is scarce, it is not suitable for mass production.
In addition, previous literature (Synthesis of Stilbene and Dihydrostilbene Derivatives and Their Value as Potential Anticancer Agents That Inhibit Tubulin Polymerization, Mark Cushman. J. Med. Chem. 1991, 34, 2579-2588,) dealt with the synthesis of stilbene and dihydrostilbene derivatives, but the method for synthesis of Erianin was not involved in particularly. It neither described the synthesizing technology and yield of the intermediate. Silyloxylated was used as phenolic hydroxyl protecting group in the article, but benzyl group is used in present invention, for the reactions of deprotection and hydrogenation can be completed at the same time, which is more simple to implement, and fit for industrial production. Besides, there was sodium hydride and sodium methylate in the Wittig reaction in above articles, but in the present invention, sodium tertiary butoxide is used, which can be more stabilization and easier to react.
In the literature concerned with the synthesizing of Erianin (Synthesis of Alkoxy-Substituted Diaryl Compounds and Correlation of Ring Separation with Inhibition of Tubulin Polymerization: Differential Enhancement of Inhibitory Effects under Suboptimal Polymerization Reaction Conditions, J. Med. Chem. 1992, 35, 1058-1067 Zelleka Getahun), the starting material for reaction was different from present invention. 3,4,5-trimethoxybenzaldehyde and isovanillin used in the present invention are common in the material market and cheap. They can be bought or produced by oneself, so as to avoid significant influence on the cost of the product caused by the change in the cost of material. According to the literature, the intermediate, cis-trans-isomer, went on for further reaction without crystallization, which was disadvantageous for the next procedure and the calculation of the yield of the product. In this invention, the cis-trans-isomer is crystallized before the next step, which would facilitate batch feeding, lower the cost and increase the yield (80.48%, as against 72% in the literature). According to the literature, there must be a step of purification by column after the hydrogen reduction reaction, so the efficiency was low. But in present invention, recrystallisation is done directly to remove benzyl-chlorination which is a coproduct in the solution. The operation is simple, advanced, and efficient, fit for industrialized production. No high vacuum distillation or reaction under high temperature and high pressure that asks for rigorous production condition but is of low yield is required in this invention. In present invention, the reaction condition is moderate, and there is no complicated but inefficient operation such as column chromatography, so the yields in every step can be controlled above 80%, both the single-step yield and overall yield being very high.
In the process of the synthesis of Combretastatin (Isolation and Synthesis of Antineoplastic Agents 291 Combretastatins A-4, A-5, and A-6, J. Med. Chem. 1995, 38, 1666-1672, George R. Pettit), the synthetic route of CA4, the intermedium of Erianin, was described, in which the phenolic hydroxyl protecting group was silyloxylated. In present invention, benzyl group is used for the direct deprotection in hydrogenation reaction. In the above article, there is sodium n-butoxide in the Wittig reaction, but present invention use potassium t-butoxide which is cheaper, safer, and easier to operate.